Enhancements in automotive sensing systems over the past several decades have provided dramatic improvements in vehicle occupant protection. Presently available motor vehicles include an array of such systems, including object detection systems that sense vehicles or other objects behind and adjacent to the vehicle. Further, object detection systems for the front of the vehicle have been used for crash avoidance systems and speed control systems that allow the following of preceding vehicles. However, these systems are generally designed to detect and classify objects that may enter a region around the vehicle. These systems do not inform the driver if the vehicle is departing from the road or current lane inadvertently.
Some systems are under development that do detect lane departure. However, these systems are typically unreliable. Such systems often use a vision sensor to detect lane demarcations on a road surface. However, if the vision sensor is unable to clearly detect the lane demarcations the system may improperly indicate a lane departure. If lane departures are falsely detected the driver will eventually ignore any warning from the lane departure system, thereby limiting its effectiveness. In addition, customer satisfaction with the system will decline, impacting the customer's overall satisfaction with the vehicle.
It is apparent from the discussion above that there is a need for an improved system for sensing when a motor vehicle is departing from the current lane.